In conventional motors having power-feeding brushes, among a plurality of segments arranged in a commutator, predetermined segments may be short-circuited. When predetermined segments are short-circuited in such a motor, current flows through segments that are not in contact with power-feeding brushes. This reduces the quantity of power-feeding brushes that are required in a motor.
For example, with the structure described above in which predetermined segments are short-circuited, the predetermined segments are short-circuited by using a short-circuit wire or by bypassing a winding wire that is wound around a core.
A motor including an equalizer (short-circuiting member) and a commutator (main body) fixed to the equalizer in the axial direction of a rotor is known in the prior art (refer to, for example, Patent Publication No. 1). The commutator includes a plurality of segments, and the equalizer includes a large number of terminals and insulating plates that are alternately laminated in the axial direction for short-circuiting predetermined segments.
A commutator including different kinds of terminals that are embedded in insulators for short-circuiting predetermined segments (where each terminal is arranged at a different position in the axial direction) is also known (refer to, for example, Patent Publication 2).
However, when predetermined segments are short-circuited by using the wire such as the short-circuit wire as described above, space for accommodating the wire needs to be provided between the commutator (segments) and the armature core. The commutator (and the armature) including the wire accommodating space is elongated in the axial direction. Further, when predetermined segments are short-circuited by the equalizer (short-circuiting member), which includes many terminals and insulating plates that are alternately laminated, the equalizer is connected to the commutator (main body) in the axial direction. This elongates the commutator (and the armature), which includes the equalizer, in the axial direction. As a result, the motor is enlarged.
In a commutator including different types of terminals that are embedded in insulators for short-circuiting predetermined segments, the terminals are accommodated in the commutator (insulators). This prevents the commutator from being elongated in the axial direction. However, with this structure, the terminals are arranged at different positions in the axial direction. Thus, different types of terminals become necessary. Accordingly, there is a need for dies corresponding to the different kinds of terminals, and different kinds of components must be handled thereby causing the assembly operation to be complicated. This increases the manufacturing cost of the commutator or the motor including the commutator.
The present invention provides a short-circuiting member, a commutator, and a method for manufacturing a short-circuiting member that prevent a commutator from being elongated in the axial direction and do not increase the number of types of components.    Patent Publication 1    Japanese Laid-Open Patent Publication No. 2000-60073    Patent Publication 2    Japanese Laid-Open Patent Publication No. 2003-189547